Clinical and biochemical characteristics of autoantibody systems in polymyositis and dermatomyositis.

P OLYMYOSITIS (PM) and dermatomyositis (DM) are inflammatory muscle diseases of unknown etiology. There is strong evidence for cellular immune mechanisms of muscle damage in these disorders. In recent years, numerous autoantibodies have been identified in patients with myositis, but their role in producing this clinical syndrome is unknown. In this report, we summarize the current state of knowledge about myositis-related autoantibodies, including characterization of the antigens, epidemiology, clinical significance. and the clues these autoantibodies may provide concerning the etiology and pathogenesis of the disease.